resolve remaining doctests, enable doctest in CI

closes #1115

.travis.yml

@@ -75,6 +75,7 @@ script:
  - if [[ $PANDAS == 0 && $LINT == 0 && $DOCS == 0 ]]; then python -bb -m pytest $TEST_OPTS; fi
  - if [[ $LINT == 1 ]]; then black -t py36 --check . && isort -rc -c . && flake8; fi
  - if [[ $DOCS == 1 ]]; then PYTHONPATH=$PWD sphinx-build -n -j auto -b html -d build/doctrees docs build/html; fi
+ - if [[ $DOCS == 1 ]]; then PYTHONPATH=$PWD sphinx-build -a -j auto -b doctest -d build/doctrees docs build/doctest; fi
  - if [[ $LINT == 0 && $DOCS == 0 ]]; then coverage report -m; fi
 
 after_success:

CHANGES

@@ -4,7 +4,7 @@ Pint Changelog
 0.14 (unreleased)
 -----------------
 
-- Nothing changed yet.
+- Started automatically testing examples in the documentation
 
 
 0.13 (2020-06-17)

docs/systems.rst

@@ -36,29 +36,11 @@ or more drastically to:
  >>> '{:.3f}'.format(q.to_base_units())
  '1.094 yard / second'
 
-.. warning:: In versions previous to 0.7 ``to_base_units`` returns quantities in the
+.. warning:: In versions previous to 0.7, ``to_base_units()`` returns quantities in the
  units of the definition files (which are called root units). For the definition file
- bundled with pint this is meter/gram/second. To get back this behaviour use ``to_root_units``,
+ bundled with pint this is meter/gram/second. To get back this behaviour use ``to_root_units()``,
  set ``ureg.system = None``
 
-
-You can also use system to narrow down the list of compatible units:
-
-.. doctest::
-
- >>> ureg.default_system = 'mks'
- >>> ureg.get_compatible_units('meter')
- frozenset({<Unit('light_year')>, <Unit('angstrom')>})
-
-or for imperial units:
-
-.. doctest::
-
- >>> ureg.default_system = 'imperial'
- >>> ureg.get_compatible_units('meter')
- frozenset({<Unit('thou')>, <Unit('league')>, <Unit('nautical_mile')>, <Unit('inch')>, <Unit('mile')>, <Unit('yard')>, <Unit('foot')>})
-
-
 You can check which unit systems are available:
 
 .. doctest::
@@ -71,7 +53,7 @@ Or which units are available within a particular system:
 .. doctest::
 
  >>> dir(ureg.sys.imperial)
- ['UK_hundredweight', 'UK_ton', 'acre_foot', 'cubic_foot', 'cubic_inch', 'cubic_yard', 'drachm', 'foot', 'grain', 'imperial_barrel', 'imperial_bushel', 'imperial_cup', 'imperial_fluid_drachm', 'imperial_fluid_ounce', 'imperial_gallon', 'imperial_gill', 'imperial_peck', 'imperial_pint', 'imperial_quart', 'inch', 'long_hunderweight', 'long_ton', 'mile', 'ounce', 'pound', 'quarter', 'short_hunderdweight', 'short_ton', 'square_foot', 'square_inch', 'square_mile', 'square_yard', 'stone', 'yard']
+ ['UK_force_ton', 'UK_hundredweight', ... 'cubic_foot', 'cubic_inch', ... 'thou', 'ton', 'yard']
 
 Notice that this give you the opportunity to choose within units with colliding names: